Stromboli , Italy :

The eruptive activity of the Stromboli volcano, after the major explosion of November 1, was characterized by an increase in explosive activity. The images, recorded by the cameras placed on the Pizzo above the Fossa and at 400 meters, made it possible to analyze the eruptive activity of the volcano and the hourly frequency of the explosions, gradually passing low values (less than 5 events / h) until 5 November, at medium-high values (between 15 and 20 events / h) until 1 December, when another major explosion occurred.

Since then, the hourly frequency of explosions has intensified further, settling on high values (between 20 and 25 events / h) between December 2 and 7. Following this evolution, the Department of Civil Protection, after hearing the competence centers of the INGV and the University of Florence, raised the alert level of Stromboli from « Verde » to « Giallo » (attention) . (Http://www.protezionecivile.gov.it/jcms/it/view_com.wp?contentId=COM66821)
In the following days, there was a slight increase in this activity, with an hourly frequency of explosions between 22 and 28 events / h. During the period under review, the explosive activity was mainly produced by two eruptive vents, located in the North crater area, and two others in the South Central crater area. All the mouths are located in the depression which occupies the terrace of the crater.

Starting at 10:40 GMT, a sudden increase in all monitored parameters was recorded on Stromboli.
The seismic tremor is very high (Figure 1) and is accompanied by a sharp increase in infrasound pressures. This seismic and infrasound activity indicates an intense projection process in the North East crater.

This activity is associated with a strong increase in the SO2 flux detected by the UV chamber, which, from 9: 40-10: 30, is at high values (182 tonnes / day for the Northeast crater).
The analysis of the thermal images at 13:25 GMT shows the beginning of a small lava overflow, limited extension on the outer edge of the crater Northeast.
The MODIS sensor records a moderate thermal anomaly of 13 MWatt today at 12:25 GMT, consistent with the strong projection activity in the Northeast crater.
The inclinometer network does not currently record significant deformations.

The phenomenon is constantly monitored by the Etneo Observatory, the Observatory of Vesuvius and the Section of the National Institute of Geophysics and Volcanology (INGV).

Source : INGV , lgs.geo.unifi.it

Ruapehu , New Zealand :

Carbon Dioxide (CO2) gas emission rates at Mt Ruapehu have returned to a more normal level. The period of slightly higher volcanic unrest appears to have ended. The Volcanic Alert Level remains at 1.
On December 5 the Carbon Dioxide (CO2) gas emission rate at Mt Ruapehu was measured as 440 tonnes/day, a substantial reduction from the rate of 2290 tonnes/day measured on November 23. An emission rate of 440 tonnes/day is less than the average emission rate over the last 10 years.

Emission rates of Sulphur Dioxide (SO2) and Hydrogen Sulphide (H2S), were also measured on December 5, both well below measurements from November 23. No additional water or gas composition data have been collected from the Crater Lake (Te Wai Ā-Moe) since mid-November. Over the last two weeks the volcanic tremor at Mt Ruapehu has been at low or moderate levels, but the strongest since late 2016. The lake temperature has risen from 36 oC to 38 oC in the last week, evidence of continued heat entering the lake.
The period of slightly higher volcanic unrest, which was inferred largely from the high CO2 gas emission rate measured on November 23, now appears to have ended.

Source :Geonet.

Agung , Indonesia :

On the basis of the results of the visual and instrumental data analysis and considering the potential threats of danger, on November 27, 2017 at 06:00, the status of G. Agung was raised from Level III (SIAGA) to Level IV (AWAS) . Since yesterday and until today visually the volcano is clearly visible until the appearance of the mist. Eruptions and puffs of gray ash – white, thick, of medium pressure, reach a height of about 1500 m above the summit and incline towards the West and the East. At night, the glow of the incandescent lava in the crater of the volcano is observed.

Seismograph records as of December 14, 2017 have noted:
4 shallow volcanic earthquakes (VB)
3 deep volcanic earthquakes (VA)
5 local tectonic earthquakes.
No earthquakes of eruption.
16 Low Frequency events.
32 earthquakes of emission.
No harmonic tremor.
A continuous tremor with an amplitude of 1 to 2 mm and a dominant value of 1 mm.

As of December 15, 2017 (00:00 to 18:00) it has been registered:
9 emission earthquakes
No earthquakes of eruption.
5 low frequency earthquakes.
5 shallow volcanic earthquakes (VB)
6 deep volcanic earthquakes (VA)
No local tectonic earthquakes.
1 harmonic tremor.
A continuous tremor with an amplitude of 1 to 2 mm and a dominant value of 1 mm.

Recommendations:
Communities around G. Agung and mountaineers / visitors / tourists must not climb, climb or do any activity in the danger zone around the G. Agung crater area and in all areas within 8 km from the crater of G. Agung. With a sectoral extension to the North-East and South-East-South-South-West up to 10 km from the crater of G. Agung. The estimated area risks are dynamic and continuously assessed and can be modified at any time based on the most recent observational data from G. Agung.

Source :VSI , Magma .

Photo : Ikoman Giri

Cumbal , Colombia :

Subject: Cumbal Volcano Activity Bulletin.The level of activity of the volcano is maintained at the level:YELLOW LEVEL ■ (III): CHANGES IN THE BEHAVIOR OF VOLCANIC ACTIVITY

Following the activity of the CUMBAL VOLCANIC COMPLEX, the COLOMBIAN GEOLOGICAL SERVICE informs that:

During the evaluated period, from December 5 to December 11, 2017, the trend of decreasing the occurrence and energy levels of seismic activity was maintained over the previous two periods of total of 316 in the previous period to 259 in the current period), most of these earthquakes are associated with fluid motions from a transient source over time, within the volcanic system. The events associated with the rock fracture were mainly near the crater of La Plazuela, northeast of the Cumbal volcanic complex, less than 14 km deep, less than 14 km from the volcano and up to 0.4 degree of local magnitude on the Richter scale.

Favorable climatic conditions at the summit made it possible to record gas emissions during the entire period evaluated, with the exception of December 6, mainly from the El Verde fumarolic fields in the north-east and Rastrojo in the south-west of the volcanic complex. The emission columns were observed of white color, of variable height and with directions of dispersion changing by the action of the wind.
The COLOMBIAN GEOLOGICAL SERVICE is attentive to the evolution of the volcanic phenomenon and will continue to inform in a timely manner of the detected changes.

Source : SGC

Dukono , Indonesia :

Level II Activity Level (WASPADA). The Dukono volcano (1229 m above sea level) has a continuous eruption. Since yesterday until this morning, visually, the volcano seems clear. Crater smoke was observed up to 600 m above the summit. The wind was blowing slightly eastward. The height of the ash column was not measured.

By the seismographs dated December 14, 2017, it was recorded:
Ash emission associated with continuous tremors of amplitude from 0.5 to 26 mm (dominant 4 mm).
5 eruption earthquake.
1 local Tectonic earthquake.
1 deep tectonic earthquake.
There was no rumbling heard from the Dukono Post, 10 km north of the summit.
Recommendation: The communities around G. Dukono and visitors / tourists should not move, climb or approach the Malupang Warirang crater within 2 km.